Biomechanical evaluation of suture–tendon interface and tissue holding of three suture configurations in torn and degenerated versus intact human rotator cuffs

Purpose The purpose of this study was to biomechanically evaluate suture–tendon interface and tissue holding of three sutures in torn and degenerated versus intact human rotator cuffs. Methods Sixty-three human rotator cuff tendons were divided into torn degenerated group (TDG), n = 21 and intact group (IG), n = 42. Ultimate tension load (UTL) and cyclic loading were tested for three arthroscopic sutures: simple, horizontal, and massive cuff sutures (MCS). Results Ultimate tension load was significantly higher ( p < 0.05) for the MCS (194 ± 68 N) in comparison with the simple (105 ± 48 N) and horizontal sutures (141 ± 49 N) in IG. In TDG, UTL was not significantly higher (n.s.) for MCS (118 ± 49 N), simple (79 ± 30 N), and horizontal sutures (107 ± 28 N) in comparison with IG. MCS (118 ± 49 N) showed no significantly superior UTL in comparison with the simple and horizontal sutures in the TDG. MCA elongation was 0.6 ± 0.7 mm in the IG and 1.3 ± 0.7 mm in the TDG, while horizontal suture elongation was 0.7 ± 0.4 mm in the IG and 1.3 ± 0.5 mm in the TDG. Simple suture elongation was 1.1 ± 0.5 mm in the IG and 1.6 ± 0.7 mm in the TDG. Conclusion Human torn and degenerated rotator cuffs have poor tissue quality, significantly lower UTL and higher cyclic elongation in comparison with intact cuffs regardless of the type of suture used for repair, which invites the need for repair techniques that grasps greater tissue volume in addition to augmentation techniques. Clinical relevance Clinicians better use repair techniques that grasp greater tissue volume (e.g. MCS, modified Mason–Allen cross bridge, double-row cross bridge, etc.) when repairing the torn and degenerated rotator cuffs.